Tag Archives: Lyme disease

Who Ate All the Peaches?

Perhaps you didn’t think much of all the little baby squirrels running about your neighborhood this past summer. We had half a dozen nests on out street, and each nest appeared to have half a dozen babies. Early in the morning I would often see the young families playing in, around, and under our neighbors cars, scampering up and down trees, and leaping about the branches. I wasn’t paying too much attention, until we began to notice large toothy chunks missing from my unripe peaches. Half eaten peaches, still on the branch, along with disappearing fruit, plagued our little tree until by harvest time we had little more than a handful, when usually we have baskets full.

We found the culprit(s) mid-summer, brazenly scurrying and chomping through the peach tree. The squirrels ate all our blueberries, too, and most recently, have been depositing the large green balls of the Black Walnut tree fruits on our front porch.

Why the squirrelnado? During the 2017 growing season there was a bumper crop of acorns, which means many more adults went into winter with a full belly and an ample supply of acorns in their pantries. A greater number than usual survived the winter, which translates to many more baby squirrels in the spring of 2018. This year’s acorn crop has been smaller than average. The squirrels are desperately trying to stockpile food. Not only are they eating foods they don’t normally eat, but they are also exhibiting extremely at risk behavior. Driving along New England highways and byways, you may have observed a great many dead squirrels as both roadkill and laying alongside the road.

If a squirrel runs out in front of your car when traveling at high speed on the highway, it is best not to swerve. I know that sounds counterintuitive, but the squirrels look at the car as a large oncoming predator. By swerving, you confuse the critter, and run the risk of injuring yourself and/or another party.

With far fewer acorns, not as many squirrels will survive the winter. Will we see an upswing in Lyme disease next summer? I imagine so. White-footed Deer Mice and Eastern Chipmunks also feed heavily on acorns and they, along with squirrels, harbor Lyme. This year there are lots of small woodland mammals the ticks can attach themselves too. Next year, not so much. With far fewer wild mammals the ticks will be looking to people and furry pets for their next meal.

Chipmunks are also a Lyme disease vector.

The Mouse That Ran Up My Dress

Well hello there little mouse! My husband Tom was releasing a mouse that was caught in his have-a-heart trap. He first opened opened the front door of the trap, with no sign of movement within, and then the back door. After a few minutes passed, out ran the little mouse, but then he froze in his tracks, only several feet from where I was standing. As I was motionless taking his photo, I think he must have thought I was a tree. He suddenly ran up my leg, up under my dress, and poked his head out from beneath my coat. It’s too bad I was holding the camera and not my husband!

Thinking about hantavirus, as well as other diseases mice carry, and just to be on the safe side, I changed my clothes and washed immediately.

Off towards the woods he ran.

Studies show how the increasing Eastern Coyote population has impacted White-footed Mice, Red Fox, and the explosion of Lyme disease. In areas where the Eastern Coyote has outcompeted the Red Fox for habitat, Lyme disease has increased. Coyotes not only kill Red Fox, they simply aren’t as interested in eating mice as are the fox.

Answer: Both the White-footed and Deer Mouse carry hantavirus, not the House Mouse. To be on the  safe side, if you find rodent droppings in your home or office, do not vacuum because that will disperse the virus throughout the air. Instead, wipe up with a dampened paper towel and discard.

Read more about the White-footed Mouse and Lyme disease here: The Mighty White-footed Mouse

Coyotes, Red Foxes, and Lyme Disease in Massachusetts

Are Coyotes the Cause of an Increase in Lyme Disease?

Struck by the recent interest in coyotes after the fascinating video Two Coyotes Versus One Deer  by Shawn Henry was posted on GMG, I became interested in reading various studies and reports about coyotes, wolves, and foxes in Massachusetts and the Northeast. My primary interest at the onset was of concern for the Red Fox (Vulpes vulpes), which has seen a tremendous decline in numbers. I wondered if the presence of coyotes (Canis latrans) was negatively impacting the Red Fox. In the past, I often saw a Red Fox in the early morning hours trotting along the shoreline at Brace Cove. I wish so much that I had filmed the last that one that I saw because it was a gorgeous scene; a strikingly beautiful creature so completely unaware of my presence and so at home in its realm, investigating rock and seaweed, pausing to sniff the air, and then resuming its journey. The last time I saw a Red Fox in our neighborhood was over three years ago. As I was reading about coyotes I learned the findings of some of the most recent studies indicate that because Eastern Coyotes out-compete the Red Fox, the coyotes are the cause of an increase in Lyme disease. More on that in a moment.

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The coyotes that now inhabit every region in Massachusetts are an invasive species. They are a hybrid cross species of the Western Coyote (found west of the Mississippi) and Red Wolf (Canis lupus rufus). “Researchers now believe that the Eastern Coyote is a hybridization between the Western Coyote and Red Wolf many generations ago in the upper Great Lakes region of the United States. It is theorized that as populations of the Western Coyote increased, they were forced to move east and north in search of food. As they moved into Minnesota they crossbred with Gray/Red Wolves and produced a genetically hardy animal able to sustain itself through New England winters.” (Mass Audubon)

Coyotes are not “re-populating” this region because this new species was never in our region.

Eastern Coyotes have extremely broad food habits and many factors affect the coyotes’ diet, including competition with other mammals, abundance of prey, season, and weather. In the Northeast, their diet consists of shrews, rabbits, voles, woodchucks, mice, deer, beaver, muskrat, weasels, squirrels, and carrion. And according to Mass Audubon, “They eat ground-nesting birds and their eggs, as well as reptiles and amphibians. When other prey is scarce they will eat a variety of insects including grasshoppers, beetles and cicadas. When animal matter is scarce, they will eat available fruits including apples, cherries, grapes, and strawberries.”

The rapid invasion of the alien Eastern Coyote has negatively impacted many sympatric native species, as the coyote has assumed the role of top-order predator. The coyote has fundamentally altered the existing ecosystem and various species have experienced population declines as a direct result of their role as coyote prey or from direct competition for food. “Culturally and ecologically significant species including Red Fox decline dramatically in response to increasing coyote populations. Eastern Coyote and Red Fox share many common habitat requirements and occupy overlapping niches. Through time, the larger and more resilient coyote is able to out-compete and displace resident fox populations.” (Department of Natural Resources, Maryland.)

Studies have shown repeatedly that Eastern Coyote predation on deer is minimal. Most herds can handle the coyotes. Typically coyotes have success with fawns that are 4-5 weeks old (after they have become more active and are not by the mother’s side), weakened and sickly adults, and deer separated from the herd. These targets represent approximately one or two percent of the total deer population. While coyote diet studies show consistently the use of deer for food, it does not appear that coyote limit deer population on a regional scale.

Although the population of White-tailed Deer has stabilized, Lyme disease continues to increase. In June of 2012 researchers at the University of California Santa Cruz published their findings from the study “Deer, Predators, and the Emergence of Lyme Disease.” (Taal Levi, lead author.)

The study found that once where there was an abundance of Red Foxes, there is now an abundance of Eastern Coyotes.  Even more significantly, fewer coyotes will inhabit an area once populated by more foxes. The greater number of foxes would have consumed a larger number of small tick-bearing animals, primarily White-footed Mice, Short-tailed Shrews, and Eastern Chipmunks, all of which transmit Lyme disease bacteria to ticks. It appears as though it is the Red Fox that once kept the population of these smaller rodents under control.

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Even when there is a threefold rise in deer population, study after study now shows that the strongest predictors of a current year’s risk of Lyme disease are an abundance of acorns two years previously. How does that work?

Many acorns = many healthy mice and chipmunks.

Many healthy mice and chipmunks  = many tick nymphs.

The following year when it may not be a bumper acorn crop = fewer mice.

Fewer mice and chipmunk = dogs and humans become vectors for the ticks.

While acorns don’t serve as a universal predictor because Lyme disease can be traced to forests where there are no oak trees, the data suggest that food sources and predators of small forest mammals are likely to be valuable in predicting Lyme disease risk for humans.

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To summarize, multiple studies suggest that the invasive Eastern Coyote out-competes and kills the native Red Fox population, which leads to a rise in the number of small animals particularly the White-footed Mouse and Eastern Chipmunk, which in turn leads to an increase in ticks that carry Lyme disease. The impact of the Eastern Coyote on native deer population is negligible. And, as many family’s can attest, the impact of the Eastern Coyote on populations of domestic cats and small dogs has been devastating.

Typically the excuse given for unwanted encounters with wildlife is that people are encroaching on the animal’s habitat. That simply is not the case with the Eastern Coyote. The Eastern Coyote is advancing on humans–and they like what they see; no large predators, a reluctance on the part of people to hunt and trap, and an abundance of food. The environmentally and culturally destructive chain reaction caused by the Eastern Coyote invasion is taking on added urgency as the coyote strikes closer and closer to home.

If confronted by a coyote, make as much noise as possible, if attacked, fight back aggressively.

Images courtesy Google image search.